Rickydotcom replied: "Allergic reactions can occur at anytime, even after 14 years. However, alarm bells went off when you mentioned "color change." You should contact the pharmacy immediately and verify that the color of the pill should be different. There are a number of different generic companies that make metoprolol, so verify that's the case. If no dispensing error has been made, speak to your doctor and to the pharmacy manager. Explain that you did fine before the generic switch. I have a couple of patients that I stock specific generics for them for this same reason.
As others have mentioned, there can be other reasons for a sudden allergic reaction, anything from a new laundry detergent or a new perfume. But rule out the medication first. By the way, if the pharmacist or his/her boss doesn't want to special order a product for you, contact the district pharmacy manager (if a chain store) or find a new pharmacy. I'll special order anything to keep a patient happy - and healthy.
Be well. I hope this helps.
Rick the Pharmacist"